I am considering upgrading my brake system on my 328i Sport Line for DD and advanced track use. I know there have been many threads discussing the M-Sport and M-Performance brakes in terms of price, appearance, and fitment. I would like to limit this post to just performance differences compared to oem brakes or other BBK systems. Specifically, how do they feel and perform on the street compared to the oem system or other BBKs. For those who have tracking experience, how do they perform on the track?

I don't think we can assume the M-Sport or M-Performance are automatically a big upgrade from stock. I have read mixed reviews on those who have upgraded to these brakes, which include some complaints of poor pedal feel compared to the oem brakes. Also, people with the BMW 135 had problems / complaints with their oem BMW/brembo equiped brakes--at least in terms of brake fade on track. The BMW M-Performance brakes, front and rear, for the F30 can be purchased for 2K--which seems like a steal. After all, Stop Tech ST-40 (6-Piston) and Brembo GT (6-Piston) brakes systems start at 3K for the fronts only. That makes me wonder whether the M-Sport or M-Performance brakes are really a big perfomance upgrade? I would truly appreciate thoughts or advice from those who have experience on this topic.

Im not an expert but Im under the impression that bigger discs n calipers should mean less fade since u have a bigger breaking-area and therefore dont need to break as heavily as u'd have to with smaller ones, assuming u have the same tires on each setup to disregard that factor. But then again u can have better pads on the smaller ones minimizing the fade. But I would assume the pads on the M and M Performance ar at least as good as the OEM ones, so they should fade a little less.